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Aims: To provide normative data for chromatic discrimination on the Farnsworth-Munsell 100 hue test particularly for observers under 23 years of age. Methods: Normal observers were screened for congenital colour vision deficiencies using the Ishihara test leaving 382 observers. Results: New total error score (TES) norms (means and 95th percentiles) are presented for each year of age from 5-22 and for 10 year age groups from the 30s to the 70s. These norms are presented as actual values (TES) and also as square root values (√TES). Other data include partial error scores for red-green and blue-yellow axes discrimination. Conclusion: This study provides the most detailed set of normative data to date.

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Studies of expertise have typically shown that experts have better memory for materials from their fields than do novices. However, previous research on memory for maps has not shown the expected effect of expertise. The present study differed from previous studies by using contour maps as well as planimetric maps. In Experiment 1 the expected superiority in memory performance was found for skilled map readers when contour maps were used, but not when planimetric maps were used. In Experiment 2, the main results of Experiment 1 were replicated, and, in addition, process tracing data were obtained during both study and test phases of contour map learning. Objective measures of attentional and retrieval focussing revealed almost no differences between the skilled and unskilled subjects. However, analyses of verbal protocols showed that the skilled subjects made more use of specialist schemata, whereas the unskilled subjects spent more time in reading place names. During recall, the skilled subjects made more use of both specialist and “lay” schemata, whereas the unskilled retrieved more place-name information. The results are interpreted in terms of a schema-based approach to expertise.

In this study of diabetic colour vision, differences in performance were found on the Pickford-Nicolson anomaloscope and the Farnsworth-Munsell 100-Hue test, between diabetics and equivalent age controls and between diabetics with retino-pathies and those with none. The discriminant function analysis used (which selects the weighted combination of the available variables) shows that the best separation into these categories (error in classification below 20%) is achieved when both colour vision variables and duration are included. Colour vision tests plus the duration variable are also useful in predicting onset of minor retinopathies in diabetics under 30 and over 60 years of age, where those patients first had no retinal damage but developed a few microaneurisms after 5 years.

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Predictions about the onset of retinopathy in 295 diabetic patients, all originally having no evidence of retinopathy, have been made in a longitudinal study over 7 yr. Out of many color vision tests and clinical variables, the best individual predictor was a measure of yellow-blue discrimination, using an anomaloscope. The other predictors of significance were the degree of blood glucose control and the duration of diabetes. Although the predictions from a linear logistic model were significant in classifying the diabetic subjects into those whose fundus will remain normal and those in whom it will develop retinopathy, the number of misclassifications was substantial. An examination of the goodness of fit between the data and the model suggested a criterion value (P) of around P = 0.3 for the probability that a patient develops retinopathy. At this value, the probability of being normal for an individual classed as normal was 0.82, and the probability of developing retinopathy for an individual classed as having retinopathy was 0.54.